Ic socket having an improved locking arrangement and method of making the same

Abstract

An IC socket ( 1 ) mounted on a printed circuit board ( 9 ) for receiving an IC package ( 10 ) includes a socket body ( 2 ), a plurality of contacts ( 3 ) received in the socket body ( 2 ), a stiffener plate ( 4 ) surrounding the socket body ( 2 ), and a locking arrangement ( 7 ) securing the stiffener plate ( 4 ) to the printed circuit board ( 9 ). The locking arrangement ( 9 ) includes a ferrule ( 70 ) fixed on the stiffener plate ( 4 ) and a screw ( 71 ) disposed within the ferrule ( 70 ) before the stiffener plate ( 4 ) mounted onto the printed circuit board ( 9 ).

1 . An IC socket mounted on a printed circuit board for receiving an IC package comprising:
 a socket body;   a plurality of contacts received in the socket body;   a stiffener plate surrounding the socket body; and   a locking arrangement securing the stiffener plate to the printed circuit board, and comprising a ferrule fixed on the stiffener plate and a screw disposed within the ferrule before the stiffener plate is mounted onto the printed circuit board.   
   
   
       2 . The IC socket as claimed in  claim 1 , wherein the stiffener plate is made of metal and defines a mounting hole, and the ferrule has a riveting portion engaging with the mounting hole via a riveting process. 
   
   
       3 . The IC socket as claimed in  claim 2 , wherein the ferrule has a guiding portion formed at a tip end thereof with a diameter smaller than that of the mounting hole. 
   
   
       4 . The IC socket as claimed in  claim 3 , wherein the guiding portion and the riveting portion together define a containing groove therebetween for receiving metal scrap detached from the riveting portion during the riveting process. 
   
   
       5 . The IC socket as claimed in  claim 1 , further comprising a gasket positioned under the mounting hole and upwardly bended to clip the stiffener plate. 
   
   
       6 . The IC socket as claimed in  claim 5 , wherein the ferrule defines a through hole and the screw has a neck portion and a head portion above the neck portion, the necking passing through the through hole. 
   
   
       7 . The IC socket as claimed in  claim 6 , wherein the ferrule further has a cavity above the through hole for receiving the head portion of the screw, the cavity communicating with the through hole and having a bigger diameter than that of the through hole. 
   
   
       8 . The IC socket as claimed in  claim 6 , wherein the screw further has a locking portion configured with screw thread thereon for engaging with a back plate under the printed circuit board. 
   
   
       9 . The IC socket as claimed in  claim 8 , wherein the locking portion of the screw has a bigger diameter than that of the through hole of the ferrule so that the screw is not able to escape away from ferrule. 
   
   
       10 . The IC socket as claimed in  claim 1 , wherein said screw is configured with larger dimensions on both ends so as to being constantly associated with said ferrule without possibility of withdrawal therefrom, either upwardly or downwardly. 
   
   
       11 . A method of making an IC socket comprising the steps of:
 providing a socket body holding a plurality of contacts therein;   providing a stiffener plate surrounding the socket body, the stiffener plate defining a mounting hole;   providing a ferrule configured with a through hole therein and a screw including a head portion and a cylindrical neck portion;   inserting the neck portion of the screw through the through hole of the ferrule and then forming screw thread on a tip end of the neck portion to produce a locking portion which is not able to pass through the through hole of the ferrule due to the screw thread; and   securely fixing the ferrule within mounting hole of the stiffener plate.   
   
   
       12 . The method as claimed in  claim 11 , wherein the stiffener plate is made of metal, and the ferrule has a riveting portion, by which the ferrule is riveted within the mounting hole. 
   
   
       13 . The method as claimed in  claim 12 , wherein the ferrule has a guiding portion formed at a tip end thereof with a diameter smaller than that of the mounting hole. 
   
   
       14 . The method as claimed in  claim 13 , wherein the guiding portion and the riveting portion together define a containing groove therebetween for receiving metal scrap detached from the riveting portion during the riveting process. 
   
   
       15 . The method as claimed in  claim 10 , wherein the ferrule further has a cavity above the through hole for receiving the head portion of the screw, the cavity communicating with the through hole and having a bigger diameter than that of the through hole. 
   
   
       16 . The method as claimed in  claim 15 , further providing a back plate under the printed circuit board, the locking portion engaging the back plate. 
   
   
       17 . An electrical connector assembly for use with an electronic package, comprising:
 a metallic stiffener plate having a plate defining a center opening and a plurality of through holes in a periphery region surrounding said center opening;   an insulative housing disposed in the center opening; and   a plurality of locking devices each including a metallic ferrule extending into the corresponding through hole; wherein   the screw defines a head at a top end region and a screw section at a bottom end region opposite to the head, and said screw section defines an outer diameter being larger than an inner diameter of the ferrule after deformation of the ferrule is performed for preventing backward withdrawal of the screw from the corresponding ferrule prior to mounting the stiffener to a printed circuit board via said locking devices.   
   
   
       18 . The electrical connector assembly as claimed in  claim 17 , wherein said deformation occurs during riveting said ferrule to the stiffener plate. 
   
   
       19 . The electrical connector assembly as claimed in  claim 18 , wherein said ferrule defines an enlarged head portion seated upon an upper face of the stiffener plate and equipped with a recess to receive said head of the screw therein for restraining downward movement of the screw. 
   
   
       20 . The electrical connector assembly as claimed in  claim 19 , further including a gasket attached upon a bottom face of the stiffener opposite to said head portion of the ferrule and seated upon the printed circuit board.